OpenFOAM/C2/Supersonic-flow-over-a-wedge/English-timed

Time	Narration
00:01	Hello and welcome to the spoken tutorial on Supersonic flow over a wedge using OpenFOAM
00:07	In this tutorial I will show you How to solve a compressible flow problem of supersonic flow over a wedge How to post process the results in paraView.
00:18	To record this tutorial I am using Linux Operating system Ubuntu version 10.04 OpenFOAM version 2.1.0 ParaView version 3.12.0
00:30	To practice this tutorial a learner should have some basic knowledge of Compressible flows andGas Dynamics
00:38	Let us now solve supersonic flow over a wedge using OpenFOAM and see the shock structure formed using paraview
00:47	The problem consists of a wedge with semi-angle of 15 degrees kept in a uniform supersonic flow
00:55	Inlet velocity is 5 meters per second
01:00	The boundary conditions are set as shown in the figure
01:05	The type of solver I am using here is rhoCentralFoam
01:10	It is a Density-based compressible flow solver It is based on central- upwind schemes of Kurganov and Tadmor
01:21	Open a command terminal to do this press ctrl +alt+ t keys simultaneously on your keyboard
01:28	In the terminal type path for supersonic flow over a wedge
01:35	In the terminal Type 'run' and press enter
01:40	cd tutorial - Press Enter cd compressible - Press Enter cd rhoCentralFoam - Press Enter
02:02	cd wedge15Ma5 and press enter
02:13	This is the name of the folder of supersonic flow over a wedge in rhoCentralFoam and press enter
02:21	Now type ls and press enter
02:24	You will see three folders : 0,constant and system.
02:29	Now open the blockMeshDict file,to do this
02:34	type cd space constant and press enter
02:41	cd space polyMesh note that M here is capital and press enter
02:49	Now type ls and press enter you can see the blockMeshDict file
02:54	To viewblockMeshDict file type gedit space blockMeshDict note that M and D here are capital and press enter
03:08	let me drag this to the capture area scroll down
03:14	In this you need to calculate the co-ordinates for the wedge
03:20	This has been already calculated and set up in the problem
03:23	The rest of the data remain the same
03:29	In boundary patches the boundaries are set as shown in the figure
03:33	Close the blockMeshDict file
03:36	in the command terminal type cd ..(dot dot) twice to return back to wedge folder
03:45	Now Open the 0 folder
03:51	To do this type cd space 0 and press enter
03:58	Type ls and press enter
04:02	This contains initial boundary condition for pressure,velocity and Temprature
04:10	Type cd .. (dot dot) and press enter.Now we need to mesh the geometry
04:19	To do this in the command terminal type blockMesh and Press Enter Meshing has been done
04:32	Now to view the geometry in the terminal 'type paraFoam' and press enter This will open the paraview window
04:45	On the left hand side of object inspector menu click APPLY
04:53	In this you can see the geometry is which is a rectangular section upstream and changes to a wedge downstream Close the paraview window
05:05	Now run the solver 'rhoCentralFoam'
05:11	To do this in the command terminal type rhoCentralFoam and Press Enter
05:20	The iterations running can be seen in the terminal window
05:24	Iterations running will stop after it converges or at the end of the time step Now the solving has been done
05:34	To visualise these results let us open the paraview window once again
05:40	In the command terminal type “paraFoam” and press Enter
05:49	Again on the left hand side of object inspector menu click APPLY
05:56	On the left side top in active variable control menu'you will see a drop down menu showing solid color. Now click on it And change from solid color to capital U'
06:14	Now make the color legend ON by clicking on left hand side top of active variable control menu and make the color legend ON click on it
06:28	On top of the paraview window you can see the VCR control Click on PLAY
06:37	You can see the final results of U velocity
06:42	Now scroll down the properties in object inspector menu on left hand side Now click on display besides properties
06:56	Scroll down and click on Rescale to Size You can see the final value of Velocity magnitude
07:05	Similarly you can select pressureYou can see the final result of pressure Now close the paraview window
07:16	You can also calculate the Mach number for the flow To do this we can use the Openfoam utility by typing Mach in the command terminal
07:26	Type Mach in the command terminal
07:29	Note that M here is capital and press enter.You can see that Mach number is calculated for each time step
07:36	Now again open the paraview window.By typing in the command terminal paraFoamand press enter
07:48	Click APPLY scroll down.In volume fields Check the Ma box and click APPLY
08:04	On top of active variable control menu click on Solid Color and change it to Ma
08:11	In the VCR control menu click on PLAY and make the color legend ON
08:21	You can see the Mach number in the color legend and corresponding colours
08:29	We notice here that when the wedge is kept in supersonic flow it produce a shock across which the flow properties like temprature, pressure and density drastically changes
08:43	Now Let me switch back to the slides' The solved tutorial can be validated with exact 'solution
08:50	available in basic books of Aerodynamics by John D Anderson
08:55	In this tutorial we learnt: Solving a compressible flow problem Velocity and pressure contour for the wedge OpenFOAM utility for calculating the Mach number
09:06	As an Assignment Vary the wedge angle between 10 ° to 15 ° to view the shock characteristic for the flow
09:14	This bring us to the end of tutorial watch The video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken_Tutorial
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09:28	The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to us at contact@spoken-tutorial.org
09:41	Spoken Tutorials project is part of Talk to a Teacher project, It is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro
09:56	This script has been contributed by Arvind M and this is Rahul Joshi from IIT BOMBAY signing off.Thanks for joining.

Contributors and Content Editors

DeepaVedartham, PoojaMoolya, Pratik kamble, Sandhya.np14